Document shredding machine



FIG. 1 is a perspective view of a document shredding machine showing our new design;

FIG. 2 is a reduced rear elevational view thereof;

FIG. 3 is a reduced top plan view thereof, the bottom being unornamented;

FIG. 4 is a reduced left side elevational view thereof. 

The ornamental design for a document shredding machine, as shown and described. 